The conventional treadmill is a commonly used interior exerciser and generally comprises folding device which allows the users to fold the treadmill for convenience of storage and transportation.
U.S. Pat. No. 5,855,537 discloses a powered folding treadmill apparatus and method, and comprises a track bed 10 with two support legs 12, 14 on two sides of the track bed 10. Each of the two support legs 12, 14 has an inclined motor 36/38 located therein so as to drive the correspondent linear actuator 44 to extend and retract. When the linear actuator is activated, the front end of the track bed can be controlled to be lifted or lowered. When the linear actuator is lowered, which pivots an arm 48, and the rear end of the track bed is lifted to an upright position by the engagement of the male and female spline structures 54, 58.
The lifting of the track bed is made by the inclined motor, the linear actuator and the arm of each of the two support legs. When the front end of the track bed is lifted, the arm is lifted by the linear actuator which is driven by the inclined motor. When the track bed is to be folded, the rear end of the track bed is lifted, the arm is lowered by the linear actuator which is driven by the inclined motor, and the male and female spline structures 54, 58 are engaged with each other. It is noted that the lifting action of the front end of the track bed and the lifting action of the rear end of the track bed are made by two individual actions. The two individual actions require precisely arrangement of the related parts and the high cost is incurred.
Furthermore, in order to ensure that the front end or the rear end of the track bed can be precisely lifted, the two sides of the track bed should be simultaneously lifted or lowered. However, the two actions are made by two individual inclined motors, when the two inclined motors are not controlled to be operated simultaneously due to the design of the electric circuits, the transmission between the inclined motors and the linear actuators, between the inclined motors and the arms or between the male and female spline structures has a time lag, the two sides of the track bed cannot move simultaneously. The design and the assembling processes have to be precise enough to achieve the purposes. The large number of parts in the inclined motors, the linear actuators and the arms also make the cost be high and have less competition in the market.
The present invention intends to provide a tilting and folding device for a treadmill to improve the shortcomings of the conventional folding devices.